Route evaluation device

ABSTRACT

Disclosed is a route evaluation device that enables traveling along a route in consideration of an operation of the driver of another vehicle, and can realize a safer traffic environment. A route evaluation device includes a route candidate generation section that generates route candidates of a host-vehicle, a route prediction section that predicts routes of another vehicle, a classification section that classifies the interference states of the route candidates of the host-vehicle and the predicted routes of another vehicle into a plurality of interference forms, and a route evaluation section that evaluates the routes of the host-vehicle on the basis of the interference forms classified by the classification section.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Phase of PCT/JP2010/059995 filedJun. 8, 2010, which claims priority of Japanese Patent ApplicationP2009-141369 filed Jun. 12, 2009.

TECHNICAL FIELD

The present invention relates to a route evaluation device thatgenerates a route of a host-vehicle for use at the time of travelingcontrol of the host-vehicle.

BACKGROUND ART

In the related art, a risk acquisition device is known which detects amovable object in the vicinity of the host-vehicle, determines thepossibility of collision of the movable object and the host-vehicle, andoutputs the possibility of collision as the degree of risk. As atechnique using the risk acquisition device, for example, a collisionprevention device is known.

For example, Patent Document 1 (JP2009-20745A) describes a collisionprevention device which calculates a plurality of possible routes of thehost-vehicle and another vehicle in the vicinity of the host-vehicle onthe basis of the traveling states of the host-vehicle and anothervehicle, and calculates the best host-vehicle route collisionprobability (host-vehicle risk) on the basis of the routes. Further, inthis collision prevention device, the best host-vehicle route collisionprobability (offset risk) is calculated on the basis of the possibleroute of the host-vehicle and the possible route of another vehiclewhich are calculated on the basis of the offset traveling state of thehost-vehicle, which is offset from the traveling state of thehost-vehicle.

CITATION LIST Patent Literature

-   -   [PTL 1] JP2009-20745A

SUMMARY OF INVENTION Technical Problem

In addition to taking into consideration of the degree of risk as in therisk acquisition device of the related art, for example, it ispreferable to generate a route in consideration of the driver of anothervehicle such that the driver of another vehicle is not forced to take asudden avoidance operation or braking operation due to traveling of thehost-vehicle.

An object of the invention is to provide a route evaluation device thatenables traveling along a route in consideration of an operation of thedriver of another vehicle, and can realize a safer traffic environment.

Solution to Problem

An aspect of the invention provides a route evaluation device. The routeevaluation device includes a route candidate generation unit thatgenerates route candidates of a host-vehicle, a route prediction unitthat predicts routes of another mobile object, a classification unitthat classifies interference forms of the route candidates of thehost-vehicle and the predicted routes of another mobile object into aplurality of interference forms, and a route evaluation unit thatevaluates the route candidates of the host-vehicle on the basis of theinterference forms classified by the classification unit.

The term “route” used herein refers to a concept including temporalelements, such as time and speed, and is different from the term “path”which does not include the concept of such temporal elements. The term“interference” refers to the host-vehicle and another vehicle crossingeach other planarly in consideration of the vehicle width and thevehicle length.

With the route evaluation device according to the aspect of theinvention, the interference forms of the route candidates of thehost-vehicle and the predicted routes of another mobile object areclassified into a plurality of interference forms on the basis of thepatterns of a plurality of interference forms stored in advance.Therefore, an interference form occurring when the host-vehicleinterferes with the route of another mobile object can be classified asone interference form, and the relevant route candidate can be highlyevaluated as a route candidate to be avoided. As a result, it becomespossible to travel along a route in consideration of an operation of thedrive of another vehicle, and a safer traffic environment can berealized.

In the route evaluation device according to the aspect of the invention,the classification unit may classify the interference forms on the basisof the behaviors of the host-vehicle and another mobile object untilinterference occurs. With this configuration, the classification unitcan classify the interference forms taking into consideration whetherthe host-vehicle interferes with the route of another mobile object oranother mobile object interferes with the route of the host-vehicle.

In the route evaluation device according to the aspect of the invention,the classification unit may classify the interference forms into atleast an interference form in which the host-vehicle interferes with theroute of another mobile object and an interference form in which anothermobile object interferes with the route of the host-vehicle, and theroute evaluation unit may highly evaluate the state, in which thehost-vehicle interferes with the route of another mobile object, as aroute to be avoided compared to the form in which another mobile objectinterferes with the route of the host-vehicle. With this configuration,interference occurring when the host-vehicle should avoid another mobileobject can be avoided. As a result, it becomes possible to travel alonga route in consideration of an operation of the driver of anothervehicle, and a safer traffic environment can be realized.

Another aspect of the invention provides a route evaluation device. Theroute evaluation device includes a route candidate generation unit thatgenerates route candidates of a host-vehicle, a route prediction unitthat predicts routes of another mobile object, an objectivization unitthat expresses interference forms of the route candidates of thehost-vehicle and the predicted routes of another mobile object byobjective numerical values, and a route evaluation unit that evaluatesthe route candidates of the host-vehicle on the basis of the numericalvalues expressed by the objectivization unit.

The term “route” used herein also refers to a concept including temporalelements, such as time and speed, and is different from the term “path”which does not include the concept of such temporal elements. Inaddition, similarly to the term “interference” described above, the term“interference” used herein refers to the host-vehicle and anothervehicle crossing each other planarly in consideration of the vehiclewidth and the vehicle length. The objective numerical value of theinterference state is calculated on the basis of the state of thehost-vehicle or another vehicle (for example, position, speed, anddirection).

With the route evaluation device according to another aspect of theinvention, the interference state is numericalized in accordance withthe prescribed rule of objective numericalization. Therefore, theinterference form in which the host-Vehicle interferes with the route ofanother mobile object can be numericalized, and the relevant routecandidate can be highly evaluated as a route candidate to be avoided. Asa result, it becomes possible to travel along a route in considerationof an operation of the driver of another vehicle, and a safer trafficenvironment can be realized.

In the route evaluation device according to another aspect of theinvention, the objectivization unit may express the interference formsby objective numerical values on the basis of the behaviors of thehost-vehicle and another mobile object until interference occurs.Therefore, the classification unit can numericalize the interferenceforms taking into consideration whether the host-vehicle interferes withthe route of another mobile object or another mobile object interfereswith the route of the host-vehicle.

In the route evaluation device according to another aspect of theinvention, the objectivization unit may calculate an interference ratiorepresenting a probability that the host-vehicle interferes with theroute of the mobile object, and the higher the interference ratio, themore highly the route evaluation unit may evaluate the relevant route asa route to be avoided. Therefore, interference occurring when thehost-vehicle should avoid another vehicle can be avoided. As a result,it becomes possible to travel along a route in consideration of anoperation of the driver of another vehicle, and a safer trafficenvironment can be realized.

According to the aspects of the invention, it becomes possible to travelalong a route in consideration of an operation of the driver of anothervehicle, and a safer traffic environment can be realized.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing the functional configuration of atraveling assist device including a route evaluation device according toan embodiment of the invention.

FIG. 2 is a diagram showing a route that is generated by a routecandidate generation section and a route prediction section of FIG. 1.

FIG. 3 is a flowchart showing an operation in the traveling assistdevice of FIG. 1.

FIG. 4 is a diagram schematically showing a problem in a routeprediction arithmetic operation of the related art.

FIG. 5 is a diagram schematically showing advantages of a routeprediction arithmetic operation in an interference evaluation method ofthe traveling assist device of FIG. 1.

FIG. 6 is a diagram illustrating traveling control of a host-vehicleaccording to a traveling assist device of the related art.

FIG. 7 is a diagram illustrating traveling control of a host-vehicleaccording to the traveling assist device of FIG. 1.

FIG. 8 is a block diagram showing the functional configuration of atraveling assist device including a route evaluation device according toanother embodiment of the invention.

FIG. 9 is a diagram showing a route that is generated by a routecandidate generation section and a route prediction section of FIG. 8.

FIG. 10 is a diagram illustrating the criterion for classification of aninterference state by a classification section of FIGS. 1 and 8.

FIG. 11 is a diagram illustrating the criterion for classification of aninterference state by the classification section of FIGS. 1 and 8.

FIG. 12 is a diagram illustrating the criterion for classification of aninterference state by the classification section of FIGS. 1 and 8.

FIG. 13 is a diagram illustrating the criterion for classification of aninterference state by the classification section of FIGS. 1 and 8.

FIG. 14 is a diagram illustrating the criterion for classification of aninterference state by the classification section of FIGS. 1 and 8.

FIG. 15 is a diagram illustrating the criterion for classification of aninterference state by the classification section of FIGS. 1 and 8,together with FIG. 14.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a traveling assist device 1 including a route evaluationdevice 60 according to a first embodiment of the invention will bedescribed with reference to FIGS. 1 to 7. In the description of thedrawings, the same parts are represented by the same reference numerals,and overlapping description thereof will be omitted. FIG. 1 is a blockdiagram showing the functional configuration of the traveling assistdevice 1 including the route evaluation device 60 according to thisembodiment.

The traveling assist device 1 includes a vehicle state detection section2, an environmental situation acquisition section 3, a vehicle controlECU (Electronic Control Unit) 6, and a traveling output section 9.

The vehicle state detection section 2 functions as vehicle statedetection means for detecting position information and vehicle speedinformation of a vehicle, and uses, for example, a GPS (GlobalPositioning System), a wheel speed sensor, and the like. The GPSacquires position information of a vehicle. The wheel speed sensor is,for example, attached to each wheel of the vehicle, and acquires thewheel speed of the vehicle. The vehicle state detection section 2 isconnected to the vehicle control ECU 6 and outputs acquired vehiclestate information, such as position information and wheel speedinformation, to the vehicle control ECU 6.

The environmental situation acquisition section 3 functions asenvironmental situation acquisition means for acquiring environmentalsituation information regarding the vicinity of a host-vehicle 81, anduses, for example, a vehicle-to-vehicle communication device, aroad-to-vehicle communication device, a radar sensor using millimeterwaves or laser, and the like. Position information and vehicle speedinformation of another vehicle (another mobile object) 82 can beacquired by using a vehicle-to-vehicle communication device and aroad-to-vehicle communication device. Position information and relativespeed information of another vehicle 82 and an obstacle on a road can beacquired by using a millimeter-wave radar sensor or the like. Theenvironmental situation acquisition section 3 is connected to thevehicle control ECU 6 and outputs acquired environmental situationinformation regarding the vicinity of the host-vehicle 81 to the vehiclecontrol ECU 6.

The vehicle control ECU 6 performs overall control of the travelingassist device 1 and primarily includes, for example, a computerincluding a central processing unit CPU, a ROM, and a RAM, which are notshown. The vehicle control ECU 6 is connected to the vehicle statedetection section 2, the environmental situation acquisition section 3,and the traveling output section 9. The vehicle control ECU 6 receivesvarious kinds of information from the vehicle state detection section 2and the environmental situation acquisition section 3, and outputsvarious kinds of information to the traveling output section 9. Thevehicle control ECU 6 has a route evaluation device 60 including a routecandidate generation section (route candidate generation unit) 61, aroute prediction section (route prediction unit) 62, a classificationsection (classification unit) 63, and a route evaluation section (routeevaluation unit) 64.

As shown in FIG. 2, the route candidate generation section 61 generatesroute candidates a₁, a₂ of the host-vehicle 81. The route candidategeneration section 61 predicts the state of future position, speed,direction, and the like of the host-vehicle 81 from informationregarding the position, speed, direction, and the like of thehost-vehicle 81 input from the vehicle state detection section 2. Theroute candidate generation section 61 generates information regardingthe predicted future state of the host-vehicle 81 as the routecandidates a₁ and a₂, and outputs the generated route candidates a₁ anda₂ to the classification section 63.

As shown in FIG. 2, the route prediction section 62 predicts routes b₁,b₂, . . . , and b_(n) of another mobile object, such as another vehicle82, on the basis of the traveling environment. The route predictionsection 62 predicts the state of future position, speed, direction, andthe like of another mobile object from information regarding theposition, speed, direction, and the like of another mobile object inputfrom the environmental situation acquisition section 3. The routeprediction section 62 predicts information regarding the predictedfuture state of another mobile object as the routes b₁, b₂, . . . , andb_(n), and outputs the predicted routes b₁, b₂, . . . , and b_(n) to theclassification section 63. In general, the routes b₁, b₂, . . . , andb_(n) of another vehicle 82 are predicted exhaustively as compared withthe ratite candidates of the host-vehicle 81.

The classification section 63 classifies the interference states of theroute candidates a₁ and a₂ of the host-vehicle 81 generated by the routecandidate generation section 61 and the predicted routes b₁, b₂, . . . ,and b_(n) of another mobile object predicted by the route predictionsection 62 into a plurality of interference forms. Specifically, theclassification section 63 classifies the interference forms into aninterference form in which the host-vehicle 81 interferes with the routeof another vehicle 82 and an interference form in which another vehicle82 interferes with the route of the host-vehicle 81. In this case, theinterference form in which the host-vehicle 81 interferes with the routeof another vehicle 82 means an interference form occurring when thehost-vehicle 81 should avoid another vehicle 82.

The route evaluation section 64 evaluates the route candidates a₁ and a₂of the host-vehicle 81 on the basis of the interference forms classifiedby the classification section 63. Specifically, the route evaluationsection 64 highly evaluates a route candidate classified by theclassification section 63 as an interference form, in which thehost-vehicle 81 interferes with the route of another vehicle 82, as aroute that the host-vehicle 81 should avoid. For example, as shown inFIG. 2, with regard to the intersections between route candidates a₁ anda₂ of the host-vehicle and the predicted routes b₁, b₂, . . . , and b₉of another vehicle, the route evaluation section 64 determines whetherthe host-vehicle 81 interferes with the route of another vehicle 82 oranother vehicle 82 interferes with the route of the host-vehicle 81.Next, with regard to the route candidates a₁ and a₂ generated by theroute candidate generation section 61, when the interference states atthe respective intersections have any intersection at which thehost-vehicle 81 interferes with the route of the another vehicle 82, theroute evaluation section 64 highly evaluates the relevant routecandidate as a route that the host-vehicle 81 should avoid. In FIG. 2, Orepresents an intersection at which the host-vehicle 81 interferes withthe route of another vehicle 82, and □ represents an intersection atwhich another vehicle 82 interferes with the route of the host-vehicle81.

The route candidate generation section 61, the route prediction section62, the classification section 63, and the route evaluation section 64primarily constituting the route evaluation device 60 may be configuredby loading a program on the computer or may be configured by separatehardware.

As shown in FIG. 1, the traveling output section 9 is connected to thevehicle control ECU 6. The traveling output section 9 receives a controlsignal of the vehicle control ECU 6 and carries out driving of thehost-vehicle 81, for example, traveling drive, a braking operation, anda steering operation. For the traveling output section 9, for example, atraveling drive ECU that controls an actuator for adjusting the openingdegree of a throttle valve of an engine, a braking ECU that controls abrake actuator for adjusting hydraulic brake pressure, a steering ECUthat controls a steering actuator for providing steering torque, and thelike are used. The traveling output section 9 carries out driving of thehost-vehicle 81, for example, traveling drive, a braking operation, anda steering operation, in accordance with a route which is highlyevaluated as a route, along which the host-vehicle 81 may travel, by theroute evaluation section 64.

Next, the operation of the route evaluation device 60 will be describedwith reference to FIG. 3. FIG. 3 is a flowchart showing a flow ofcharacteristic processing which is executed by the route evaluationdevice 60.

First, the vehicle state detection section 2 acquires the state(position, speed, and the like) of the host-vehicle 81 (S01). Then, thevehicle state detection section 2 outputs the acquired information tothe vehicle control ECU 6.

Next, the environmental situation acquisition section 3 acquires theposition and state of another object in the vicinity of the host-vehicle81 (S02), and outputs the acquired information to the vehicle controlECU 6. Hereinafter, it is assumed that the position of another object isthe value regarding the center of another object, and the state ofanother object is specified by the position, speed, and the like.

From a technical viewpoint, when an arithmetic operation is carried outto generate a trace in a subsequent step, it is important that aprediction arithmetic operation is terminated in a predetermined period,regardless of whether or not the host-vehicle 81 reaches a prescribedlocation (destination or an intermediate location similar to thedestination). In general, there is no location on a road where safety isensured in advance. For example, as shown in FIG. 4, when it ispredicted that a host-vehicle O₁ which is traveling on a three-lane roadR_(d) sequentially reaches locations Q₁, Q₂, and Q₃ set in advance,taking into consideration a case where the host-vehicle O₁ substantiallytravels in a straight line along the same lane toward the set locations,if another vehicle O₃ takes a route B₃, another vehicle O₂, may take aroute B₂ to avoid risk and may enter a lane on which the host-vehicle O₁is traveling. Thus, in the case of the route prediction arithmeticoperation of the related art, it is not guaranteed in advance that thehost-vehicle O₁ is traveling safely toward the locations set in advance.

In this embodiment, since an optimum route is determined every time,instead of determining a location, such as a destination, to be reachedby the host-vehicle O₁ in advance, for example, a route B₁ shown in FIG.5 can be selected as the route of host-vehicle O₁ under the samesituation as in FIG. 4, and risk can be accurately avoided at the timeof traveling of the host-vehicle O₁, thereby ensuring safety.

Returning to FIG. 3, the route prediction section 62 predicts the futureposition and state of another object from information regarding theposition and state of another object acquired by the environmentalsituation acquisition section 3, and predicts the routes b₁, b₂, . . . ,and b₉ of another object shown in FIG. 2 (S03). In the followingdescription, description will be provided for a case where anotherobject is another vehicle 82, but another object may be a person, anobstacle, or the like other than a vehicle.

Next, the route candidate generation section 61 predicts the futureposition and state of the host-vehicle 81 from information regarding thestate of an object in the vicinity of the host-vehicle 81 acquired bythe vehicle state detection section 2, and generates the routecandidates a₁ and a₂ shown in FIG. 2 (S04). Specifically, the routecandidate generation section 61 generates a temporal-spatial routeconstituted by time and space for each object. In generating the route,it is assumed that the total number of objects (including thehost-vehicle 81) acquired by the environmental situation acquisitionsection 3 is K, and an arithmetic operation is carried out N_(k) timesto generate a route for one object O_(k) (where 1≦k≦K, k is a naturalnumber) (in this way, k and N_(k) are all natural numbers). It is alsoassumed that the time (trace generation time) for generating a route isT (>0). The route may be calculated by a known method, for example, amethod described in Japanese Unexamined Patent Application PublicationNo. 2007-230454.

Next, the classification section 63 determines the interference statesof the route candidates a₁ and a₂ of the host-vehicle 81 generated bythe route candidate generation section 61 and the predicted routes b₁,b₂, . . . , and b₉ of another mobile object predicted by the routeprediction section 62 (S05). Specifically, as shown in FIG. 2, withregard to the intersections between the route candidates a₁ and a₂ ofthe host-vehicle 81 and the predicted routes b₁, b₂, . . . , and b₉ ofthe another vehicle 82, it is determined whether the host-vehicle 81interferes with the route of another vehicle 82 or another vehicle 82interferes with the route of the host-vehicle 81. When theclassification section 63 classifies the interference states, anyclassification method in consideration of another vehicle may be used.For example, classification based on the mechanical conditions ofsmoothness (curvature, acceleration/deceleration, and the like) of aroute immediately before interference, classification based on thesocial norms, such as the observance level of the traffic rules ormanners, the fault proportion of automobile insurance, and the judicialprecedents, classification (paying closer attention to a bicycle and asmall vehicle) in consideration of vehicle performance, and the like maybe used.

Next, the classification section 63 classifies the route candidates byinterference forms on the basis of the interference states determined inS05 (S06). Here, the route candidates are classified into “aninterference form in which the host-vehicle 81 interferes with the routeof another vehicle” and “an interference form in which another vehicle82 interferes with the route of the host-vehicle”. As shown in FIG. 2,when one of the route candidates a₁ and a₂ has any intersection(indicated by O in FIG. 2) where the host-vehicle 81 interferes withanother vehicle, the classification section 63 classifies the relevantroute candidate as “the interference form in which the host-vehicle 81interferes with the route of another vehicle”. Referring to FIG. 2, theroute candidate a₁ has an intersection (indicated by O in FIG. 2) wherethe host-vehicle 81 interferes with the route of another vehicle, suchthat the route candidate a₁ is classified into “the interference form inwhich the host-vehicle 81 interferes with the route of another vehicle”.Meanwhile, the route candidate a₂ has only an intersection (indicated by□ in FIG. 2) where another vehicle 82 interferes with the route of thehost-vehicle but has no intersection (indicated by O in FIG. 2) wherethe host-vehicle 81 interferes with the route of another vehicle, suchthat the route candidate a₂ is classified into “the interference form inwhich another vehicle 82 interferes with the route of the host-vehicle”.In this case, no route candidate has “the interference form in whichanother vehicle 82 interferes with the route of the host-vehicle” (S06:NO), the process returns to Step S04, and route candidates are generatedagain (S04).

Next, in Step S06, when the route candidates a₁ or a₂ have “theinterference form in which another vehicle 82 interferes with the routeof host-vehicle” (S06: YES), the route evaluation section 64 highlyevaluates the relevant route candidate as a route that the host-vehicle81 should travel (S07). Then, the traveling output section 9 carries outdriving of the host-vehicle 81, for example, traveling drive, a brakingoperation, and a steering operation, in accordance with a route which ishighly evaluated as a route, along which the host-vehicle 81 may travel,by the route evaluation section 64 (S08).

As described above, according to the traveling assist device 1 of thisembodiment, the classification section 63 classifies the interferenceforms on the basis of a plurality of interference forms stored inadvance, and the route evaluation section 64 evaluates the routecandidates on the basis of the classification result. Therefore, aninterference form in which the host-vehicle 81 interferes with the routeof another vehicle 82 can be classified as one interference form, andthe relevant route candidate can be highly evaluated as a routecandidate to be avoided. As a result, it becomes possible to travelalong a route in consideration of an operation of the driver of anothervehicle 82, and a safer traffic environment can be realized.

With regard to traveling control when a vehicle enters a main road 90continuously with another vehicle 82 a at a T-junction, the effects ofthe traveling assist device 1 of this embodiment will be described withreference to FIGS. 6 and 7.

According to the traveling assist device of the related art, travelingcontrol of the host-vehicle 81 is carried out in accordance with a routewhich is determined to be low risk, regardless of the interference formsof the route candidates of the host-vehicle and the predicted routes ofanother vehicle. For this reason, when the degree of risk is low, forexample, as shown in FIG. 6, even when a route along which thehost-vehicle 81 enters the main road 90 interferes with the route ofanother vehicle 82 a, traveling control is carried out to allow thehost-vehicle 81 to enter the main road 90. In this case, the movement ofthe host-vehicle 81 causes interference with the route of anothervehicle 82 a, that is, interference occurring when the host-vehicle 81should avoid another vehicle 82 a. For this reason, the driver ofanother vehicle 82 a may be forced to take a sudden avoidance operationor braking operation.

Meanwhile, according to the traveling assist device 1 of thisembodiment, with regard to a plurality of route candidates, even when itis determined that the route along which the vehicle enters the mainroad 90 is lowest risk, if the classification section 63 classifies therelevant route into “interference form in which the host-vehicle 81interferes with the route of another vehicle”, the route evaluationsection 64 highly evaluates the relevant route as a route that thehost-vehicle 81 should avoid. Then, the route evaluation section 64highly evaluates a route, which is classified as “the interference formin which another vehicle 82 b interferes with the route of thehost-vehicle” by the classification section 63, that is, as shown inFIG. 7, a route along which the vehicle does not enter the main road 90as a route that the host-vehicle 81 should travel. Therefore,interference occurring when the host-vehicle 81 should avoid anothervehicle 82 a can be avoided. As a result, it becomes possible to travelalong a route in consideration of an operation of the driver of anothervehicle 82 a, and a safer traffic environment can be realized.Meanwhile, another vehicle 82 b encounters interference occurring whenanother vehicle 82 b should avoid the host-vehicle 81, such that anothervehicle 82 b can avoid interference in cooperation with the host-vehicle81.

Although the embodiment of the invention has been described, theinvention is not limited to the above-described embodiment, and variousmodifications or changes may be made without departing from the scope ofthe invention.

Although in the foregoing embodiment, as shown in FIG. 1, the examplewhere the route evaluation device 60 includes the route candidategeneration section 61, the route prediction section 62, theclassification section 63, and the route evaluation section 64 has beendescribed, the invention is not limited thereto. For example, as shownin FIG. 8, a route evaluation device 65 may include a route candidategeneration section 61, a route prediction section 62, an objectivizationsection (objectivization unit) 66, and a route evaluation section (routeevaluation unit) 67. The route candidate generation section 61 and theroute prediction section 62 are the same as those in the routeevaluation device 60 of the foregoing embodiment, and thus descriptionthereof will not be repeated.

As shown in FIG. 9, the objectivization section 66 expresses theinterference states of route candidates a₁₁, a₁₂, and a₁₃ of thehost-vehicle 81 generated by the route candidate generation section 61and predicted routes b₁₁, b₁₂, . . . , and b₂₀ of another vehicle 82predicted by the route prediction section 62 by objective numericalvalues. Specifically, the objectivization section 66 calculates ananother-vehicle interference ratio. The term “another-vehicleinterference ratio” refers to the ratio of intersections (indicated by Oin FIG. 9) where the host-vehicle 81 interferes with the route ofanother vehicle from among all the intersections of the route candidatesa₁₁, a₁₂, and a₁₃ and the predicted routes b₁₁, b₁₂, . . . , and b₂₀.Referring to FIG. 9, the route candidate a₁₁ has 10 intersections intotal and has eight intersections (indicated by O in FIG. 9) where thehost-vehicle 81 interferes with the route of another vehicle, such thatthe another-vehicle interference ratio becomes 80%. Similarly, theanother-vehicle interference ratio of the route candidate a₁₂ becomes50%, and the another-vehicle interference ratio of the route candidatea₁₃ becomes 0%.

The route evaluation section 67 evaluates the route of the host-vehicle81 on the basis of the numerical values expressed by the objectivizationsection 66. Specifically, the route evaluation section 64 highlyevaluates a route candidate having a low another-vehicle interferenceratio expressed by the objectivization section 66 as a route that thehost-vehicle 81 should travel. For example, the route evaluation section67 highly evaluates a route candidate having an another-vehicleinterference ratio equal to or smaller than 20% as a route that thehost-vehicle 81 should travel. The critical value of the another-vehicleinterference ratio may be appropriately set.

According to the route evaluation device 65 of this embodiment, theinterference forms are numericalized in accordance with the prescribedrule of objective numericalization. Therefore, an interference form inwhich the host-vehicle 81 interferes with the route of another vehiclecan be specified, and the relevant route candidate can be highlyevaluated as a route candidate to be avoided. As a result, travelingalong a route in consideration of an operation of the driver of anothervehicle 82, and a safer traffic environment can be realized.

As shown in FIG. 8, the traveling assist device 1 may further include adisplay section 8. The display section 8 is means for displaying thecontents of the route candidates evaluated by the route evaluationsection 67, and for example, displays the contents on a monitor orprojects the contents onto a windscreen. Specifically, the displaysection 8 displays a route specified as “the interference form in whichanother vehicle interferes with the route of the host-vehicle” and aroute specified as “the interference form in which the host-vehicleinterferes with the route of another vehicle” based on the evaluation ofthe route candidates by the route evaluation section 67 with differentcolors. Therefore, it is possible to display for the driver a route thatthe host-vehicle should travel or a route that the host-vehicle shouldavoid.

The traveling assist device 1 may have the display section 8 but may nothave the traveling output section 9. In this case, it is possible forthe driver to recognize a route specified as “the interference form inwhich another vehicle interferes with the route of the host-vehicle”. Inthis case, the driver can control the host-vehicle in accordance with aroute displayed on the display section 8. As a result, it becomespossible to travel of the host-vehicle 81 along a route in considerationof an operation of the driver of another vehicle 82, and a safer trafficenvironment can be realized.

In the traveling assist device 1 of the foregoing embodiment, when theclassification section 63 classifies the interference states, anyclassification method in consideration of another vehicle may be used,and for example, classification based on the mechanical conditions ofsmoothness (curvature, acceleration/deceleration, and the like) of aroute immediately before interference, classification based on thesocial norms, such as the observance level of the traffic rules ormanners, the fault proportion of automobile insurance, and the judicialprecedents, classification (paying closer attention to a bicycle and asmall vehicle) in consideration of vehicle performance, and the like maybe used. Hereinafter, the method of classifying the interference statesby the classification section 63 will be described in detail.

For example, as shown in FIG. 10, it may be determined whether thehost-vehicle 81 is likely to interfere with the route of another vehicle82 or not on the basis of an angle α between the direction of thehost-vehicle 81 and the traveling direction of a region A1 where thehost-vehicle 81 is located. For example, when the angle α between thedirection of the host-vehicle 81 and the traveling direction of theregion A1 where the host-vehicle 81 is present is equal to or greaterthan a predetermined angle (for example, 45°), it may be determined thatthe host-vehicle 81 interferes with the route of another vehicle 82.

For example, as shown in FIG. 11, it may be determined whether thehost-vehicle 81 is likely to interfere with the route of another vehicle82 or not on the basis of the priorities of a region A3 where thehost-vehicle 81 is located and a region A2 where another vehicle 82 islocated. For example, when the region A3 where the host-vehicle 81 islocated has a priority lower than the region A2 where another vehicle 82is located, it may be determined that the host-vehicle 81 interfereswith the route of another vehicle 82. In comparison of the priorities ofthe region A3 where the host-vehicle 81 is located and the region A2where another vehicle 82 is located, at an intersection shown in FIG.12, it may be determined that the host-vehicle 81 is likely to interferewith the route of another vehicle 82. The priority based on signalinformation as well as the priority based on the region where thehost-vehicle 81 is located may be used. For example, a vehicle whichruns into a green light has high priority, and a vehicle which runs intoa red light has low priority.

For example, as shown in FIG. 13, it may be determined whether thehost-vehicle 81 is likely to interfere with the route of another vehicle82 or not on the basis of road markings 91 and 92. When the road marking91 is a white line and the road marking 92 is a yellow line, if thehost-vehicle 81 which is traveling in a region A1 changes lane to aregion A2, the host-vehicle 81 is violating the traffic rules. Withregard to traveling which violates the traffic rules, it may bedetermined that the host-vehicle 81 interferes with the route of anothervehicle 82. For the determination regarding violation of the trafficrules, road signs as well as road markings may be used.

For example, as shown in FIG. 14, it may be determined whether thehost-vehicle 81 is likely to interfere with the route of another vehicle82 or not by using the parts where the host-vehicle 81 and anothervehicle 82 interfere with each other. In FIG. 14, “A” indicates that thehost-vehicle 81 interferes with the route of another vehicle 82, and “B”indicates that another vehicle 82 interferes with the route of thehost-vehicle 81. For example, as shown in FIG. 15, when the frontsurface of the host-vehicle 81 in the traveling direction and the sidesurface of another vehicle 82 in the traveling direction interfere witheach other, as shown in FIG. 14, it may be determined that thehost-vehicle 81 interferes with the route of another vehicle 82.

INDUSTRIAL APPLICABILITY

According to the invention, it is possible to travel along a route inconsideration of an operation of the driver of another vehicle, and canrealize a safer traffic environment.

The invention claimed is:
 1. A route evaluation device comprising: anelectronic control unit including a central processing unit, theelectronic control unit configured to: generate a plurality of routecandidates of a host-vehicle on the basis of an input from a vehiclestate detection section; predict a plurality of routes of another mobileobject on the basis of an input from an environmental situationacquisition section; calculate a plurality of intersections of each ofthe plurality of route candidates of the host-vehicle with the pluralityof routes of another mobile object; determine whether the host-vehicleinterferes with the route of another mobile object or another mobileobject interferes with the route of the host-vehicle for the pluralityof intersections, on the basis of an angle between the direction of thehost-vehicle and a traveling direction of a region where thehost-vehicle is located and a region where another mobile object islocated, priority based on signal information, violation of trafficrules, or parts whether the host-vehicle and another mobile objectinterfere with each other; calculate a ratio of (a) to (b), wherein (a)is the number of intersections where the host-vehicle interferes withthe route of another mobile object of each of the plurality of routecandidates of the host-vehicle and (b) is the number of allintersections of each of the plurality of route candidates of thehost-vehicle; select a route candidate, which as the lowest ratio, asthe route that the host-vehicle should travel; and send the selectedroute to at least one of a travel output section carrying out drivingand a display section in which the selected route is displayed on thedisplay section.
 2. The route evaluation device according to claim 1,wherein the electronic control unit is configured to select a routecandidate, which has no intersection where the host-vehicle interfereswith the route of another mobile object, as the route that thehost-vehicle should travel.